This invention relates to post valve yoke connections. Specifically this invention relates to a system for quickly engaging and disengaging a yoke to a post valve of a tank for receiving a supply of compressed gas.
Yokes for mounting to post valves on tanks or cylinders of compressed gases are known in the art. Yokes provide a tank with a relatively safe connection to a pressurized supply of a gas for filling the tank. One example of a prior art yoke is the CGA 870 Yoke. This device is specifically designed to mount on a CGA 870 post valve of a tank to supplying oxygen gas for filling the tank. Such tanks are commonly used to supply the oxygen needs for medical devices. FIG. 1 shows an example of such a prior art yoke 310. The yoke 310 includes a yoke body 312 with an opening 316. The opening 316 is operative to accept a post valve 320 of a tank 318 therethrough. When the tank 318 is filled from a gas supply source, the pressures involved typically range between 2000 psi and 3000 psi. The yoke includes a passageway 328 through which gases may be supplied to the tank.
Prior art yokes include a hand wheel or a tee-bar 314. By applying a rotational force to the tee-bar 314 a threaded pin 322 rotates so as to urge the post valve into sealed engagement with the yoke. To facilitate proper alignment of the post valve 320 with the yoke 310, the yoke includes standardized index pins 324 which are operative to mate with corresponding holes in the post valve.
A typical tank can be mounted to a yoke, filled with a gas, such as oxygen, and dismounted from the yoke within several few minutes. Unfortunately the manual act of rotating the tee-bar for engaging and disengaging the yoke accounts for a significant portion of time to fill a tank. For large suppliers of compressed tanks of oxygen, a significant amount of the cost of labor to fill tanks is consumed by the prior art, manual operation of rotating each tee-bar a plurality of times to engage, and disengage yokes from post valves. Consequently, there exists a need for a system of engaging and disengaging a yoke to a tank which is faster and less time consuming. There further exists a need for system of connecting disconnecting multiple tanks at one time that is faster and less time consuming.
Prior art yoke post valves and the heads of tanks are manufactured with sizes and dimensions that conform to Compressed Gas Association (CGA), ANSI, and international standards. This enables a technician to mix and match yoke post valves from a plurality of different manufacturers with tanks from a plurality of different manufacturers of the same type. In this manner all CGA 870 Yokes will be compatible with all CGA 870 tanks, regardless of who manufactures them.
Unfortunately, in practice there are slight variations in tolerances between different yokes and tanks of the same type even by the same manufacturers. These variations are typically the result of the seals and gaskets between the post valves and the yoke which have small differences in dimension and size. These variations can range as high as {fraction (1/32)} of an inch. With a prior art yoke, the tee-bar must be manually rotated by different amounts to compensate for these variations. Consequently there exists a need for a faster mechanism for engaging a yoke post valve to a tank that does not require manual adjustments to compensate for variations in sizes of seals, valves, and the yoke itself.
It is an object of the exemplary form of the present invention to provide an improved yoke for mounting to a post valve of a tank.
It is a further object of the exemplary form of the present invention to provide a yoke that is operative to quickly engage and disengage with a tank.
It is a further object of the exemplary form of the present invention to provide a system for engaging and disengaging a plurality of yokes to tanks.
It is a further object of the exemplary form of the present invention to provide a system for automating the engagement and disengagement a plurality of yokes to tanks.
It is a further object of the exemplary form of the present invention to provide a yoke that is operative to automatically compensate for differences in sealing tolerances between the post valve of a tank and the yoke.
Further objects of the present invention will be made apparent in the following Best Modes for Carrying Out Invention and the appended claims.
The foregoing objects are accomplished in one exemplary embodiment of the invention by a tank mounting system that is operative to hydraulically connect a plurality of tanks to a gas system. The system includes a rack which is operative to mount each tank to a corresponding yoke post valve. All of the yokes are in operative connection with a common passageway for directing gases through the system. The system further includes a hydraulic pump. Each of the yokes includes a hydraulic cylinder that is integral with the yoke. Each hydraulic cylinder is operative to urge the post valve of a tank into sealed engagement with the yoke responsive to hydraulic pressure. Each hydraulic cylinder is further operative to disengage the post valve of a tank with the yoke responsive to hydraulic pressure.
The hydraulic pump is operative to controllably supply the hydraulic pressure to each of the yokes. In the exemplary embodiment the hydraulic pump controls the hydraulic pressure responsive to a valve controlled flow of a pressurized supply of gas. In this described embodiment, the pressurized gasses are supplied by a shop air compressor. However, alternative embodiments may use any moderate pressure source of gases to operate the hydraulic pump.
By manipulating the flow of shop air to the hydraulic pump, the present invention enables an operator to simultaneously control the engagement and disengagement of a plurality of yokes to corresponding tank post valves. This described system significantly reduces the amount of labor and time that is necessary for connecting multiple tanks to a supply of pressurized gas such as oxygen.
In another exemplary embodiment of the present invention, the system may include a yoke that is manually engaged and disengaged from a post valve of a tank with a lever arm. The lever arm is operative to urge a plunger or pin toward the post valve for engaging the post valve to the yoke. Once engaged the lever arm includes a trigger locking mechanism for maintaining the yoke in an engaged position. By releasing the trigger lock, the lever is operative to raise the plunger and disengage the tank from the yoke. Such a manual lever provides a much faster method of engaging and disengaging a yoke to a post valve of a tank than the prior art yoke described previously.
To compensate for variation in tolerances between the seals of the yoke and the post valve of the tank, this described embodiment of the lever operated yoke, includes a plunger which is automatically operative to adjust in height responsive to the variations in sizes of the seals. The plunger includes a retractable portion that is biased into an extended position by a plurality of internal compression spring washers. For thicker or thinner seals between the yoke and post valve, the compression spring washers are operative to compress to enable the retractable portion to retract a small amount. By retracting, the pin is operative to change in length responsive to the engaging forces caused by the larger seals.
The present exemplary invention enables a plurality of tanks to be filled much faster than prior art methods. In one exemplary system for filling tanks, multiple tanks are placed on a rack which includes either the hydraulic yokes and/or the manual lever operated yokes of the present invention. Each of the yokes on the rack are connected to a common passageway. The exemplary hydraulic yokes may be automatically engaged to a corresponding tank responsive to the operation of the hydraulic pump. The exemplary lever operated yokes are manually engaged to a corresponding tank by moving their respective lever arms to an engaged position.
To prepare each tank for filling, the post valve of each tank are manually opened so as to be in fluid communication with the common passageway. A vacuum source may then be placed in operative connection with the common passageway to remove any residual gases that may be present in the tanks.
To fill the tanks with a compressed gas, the passageway is placed in operative connection with a high pressure source of the gas. Once filled, the post valves may be closed, the gas pressure in the common passageway may be normalized with a bleeder, and the yokes disengaged from the tanks. The exemplary hydraulic yokes may be automatically disengaged responsive to operation of the hydraulic pump. The exemplary lever operated yokes may be manually disengaged by moving their respective lever arms to a disengaging position. Thus exemplary hydraulic and lever operated yokes of the present invention provide a safe and fast method of connecting individual and multiple pressurized tanks to a high pressure supply of a gas. Each of the exemplary embodiments are operative to provide a longitudinal force that moves a pin or plunger in a linear reciprocating motion. It is to be understood that a linear reciprocating motion is defined herein as a generally straight back and forth motion without the pin or plunger revolving about its axis.